What he says is true, you will find much more at the pay place. However, going off to look on your own at least gives you a chance to find a rarer type of trilobite. At the pay place they keep the layers and beds that seem to have rarer specimens roped off from customers. I'm not sure if they actually confiscate specimens if someone were somehow able to finder a rarer species, but it's not likely they will find one anyway. There's one spot I need to revisit where I found the bottom half of a really large one. Unfortunately, I set it down for a moment and then was unable to find it again after looking everywhere at dusk. Still, it was evidence of larger/rarer trilobite species in the area. I tend to try to avoid the black shale myself. Prefer the Marjum Formation and Weeks Formation to the Wheeler Shale. Below is the first trilobite I ever found that I mentioned in some of our correspondence. It's a Modocia Typicalis in tan shale of the Marjum Formation. They aren't that concentrated in that area, but there are some there. Maybe a little more like nuggetshooting in a sense. At the pay place the value of the trilobites will normally run from approx. $5 to $20 vs. $80 to $300+ for rarer specimens.